The present invention relates to a collator for use in combination with an apparatus such as a copying machine, a printing machine and the like which discharges copies of original in succession.
Such a collator is often used in combination with an electrophotographic copying machine and successive copies of an original supplied from the machine are delivered into respective bins or trays.
Such a collator can be roughly classified into three types depending on a manner of delivering the copies into the bins. In a first type, a number of bins are arranged fixedly and a distributor comprising a deflector and a copy feed mechanism is moved along a series of bins. In a second type, a series of bins are moved with respect to a copy supply position fixedly arranged in the collator. In a third type, a series of bins are fixedly arranged and at an inlet of each bin is arranged a claw like deflector. While the copies are fed along a series of bins, the deflectors of successive bins are driven to deliver the successive copies into the successive bins. The first and the third types of collator mentioned above can be comparatively small in size and could be preferably combined with a high speed copying machine. However, in the second type of collator, since the heavy bins must be driven, it could not preferably be combined with a high speed copying machine, and further requires a large space for a movement of the bins.
The present invention is to provide a collator belonging to the first and the third types of collator mentioned above. In such a collator, the distributor must be returned to an initial position after the collating operation for the last copy of a certain original has been finished, but prior to an arrival of the first copy of a next original at the collator and then the deflector at an initial position is driven. Hereinafter, said initial position is called as "home position". In Japanese Utility Model Application Publication No. 47,956/78, there is disclosed such a collator, in which a number of bins are arranged vertically one above the other, and a distributor is arranged movably from the uppermost bin to the lowermost bin so as to deliver each copies of an original into respective bins. In this collator, the distributor is returned to the home position upon actuation of a print start switch of a copying machine. Further Japanese Patent Application Publication No. 8,665/75 also discloses a similar collator in which a distributor is returned to the home position at a timing when a time period J has been elapsed after detection of the copy, said time period J being defined by T&gt;J&gt;t, wherein t is a time interval of successive copies of the same original and T is a time interval between the last copy of a certain original and the first copy of a next document. These collators can be effectively used in combination with usually available copying machines in which a single exposure of an original can form a single copy thereof and multiple copies of the original are obtained only by means of multiple exposures of the same original, and thus there is a substantial time for removing the first original from the copying machine and setting the next original, and thus said time interval T is a long.
As disclosed in Japanese Patent Laid-Open Publication No. 12,986/80 there has been developed a retention type copying machine in which a plurality of copies of an original can be obtained from the same and single electrostatic charge image once formed by subjecting it to development and transfer repeatedly. In such a copying machine of retention type, the exposure and scanning of the second document can be initiated before a completion of a duplicating operation for the first document and thus, the time interval T from the last copy of a document to the first copy of a next document can be materially shortened and, in an extreme case, can be made identical with the time interval between successive copies of the same document. In case of adopting the known collators described in the above mentioned publications Nos. 8,665/75 and 47,956/78 to the retention type copying machine, it is necessary to return the distributor to the home position during said short time interval T. However, this is very difficult. In an extreme case, if the number of copies to be formed for a document is large, the first copy of the second document might arrive at the first bin corresponding to the home position before the last copy of the first document has not yet been completely delivered to the bin.
In order to solve the above mentioned problem, for example, there have been proposed such methods that the time interval T is materially made long so as to compensate a returning time of the distributor by feeding a copy in the collator at a higher speed than in the copying machine, and that the collating operation is performed at both directions in a reciprocating manner of the distributor. However, in the former method, there occurs various technical problems due to high copy travelling speed. In the latter method, the controlling of the distributor is liable to be complex very much, and further this collator could not be used in such a case that the numbers of copies of successive originals are varied successively.
On the other hand, there have been proposed various collators which could be combined with the copying machine of retention type mentioned above. For instance, a number of bins are arranged vertically and successive copies are fed along the bins downward and are delivered into the bins from the lowermost bin. In such a collator, the distributor is returned to the lowermost bin at the home position after the last copy of a document has been completely delivered into a bin, and thus, if the returning speed of the distributor is made at least equal to the copy feeding speed, the first copy of a next document can be correctly delivered into the lowermost bin even in case that the time interval T between the last copy of a certain document and the first copy of the next document is very short. Therefore, a plurality of copies of successive documents can be collated effectively. However, in such a collator, since the home position is set at the lowermost bin and the copies are successively collated toward the upper bins, it is very inconvenient for the operator to take the collated copies out of the bins, especially when the number of copies to be formed for respective originals is relatively small. In order to avoid such a drawback, it has been also proposed to feed the copies in a direction from the lowermost bin to the uppermost bin and are successively delivered into the bins from the uppermost one. In such a collator, the operator can easily take out the collated copies, because the home position is set at the uppermost bin and copies are successive delivered downward from the uppermost bin. However, usually the copying machine has its copy outlet at a relatively upper position and thus, the collator should be provided with a copy feed mechanism for feeding the copy supplied from the copying machine to the lowermost bin. Therefore, the copy feed mechanism is liable to be large in size and complicated in construction and further since the copy has to travel along a very long and complicated path there might occur paper jamming.